This invention relates to an apparatus for machining valve seats and more particularly for apparatus for machining seats of large valves in the field.
Large stop valves for steam turbines are formed from forgings weighing hundreds of tons and repairing the seat ring within the valve when the valve is in place in the piping saves down time and the cost of removal of the valve for repair of the valve seat. In place repair consisted of welding and then hand grinding and lapping the seat rings.